I can answer that for you. No, the US military does not acquire private companies, except in extraordinary circumstances of national security (think: WW2 type events). They'd only do it if the company possesses something of extreme strategic importance and could no longer operate as an on-going concern, and the first thing they'd do is try to arrange a sale to another friendly defense contractor. Buying a private company would be the very last thing they would do in the chain of actions there; further, what they would do, is purchase the technology, not the corporation.

Accordingly, the theory about Theranos being set-up to be sold to the DoD, falls entirely flat.